1. Field of the Invention
The present invention relates to an apparatus for recording and/or reproducing information on or from a recording medium having a recording region divided into a plurality of recording areas or sectors.
2. Description of the Prior Art
In the information recording/reproducing apparatus for performing data recording or reproduction on the sector basis, the information must be able to be recorded or reproduced at or from a designated sector. In this connection, it is noted that in the case of the information recording/reproducing apparatus in which a recording medium exhibiting poor error-free characteristics such as an optical disc, there may make appearance a defective sector which must be identified before recording or through confirmation of the written data. In the system in which the address of the sector where data is to be recorded is directly designated by the user, the data must be able to be recorded notwithstanding of the presence of the defective sector. Accordingly, there is required an alternate sector in which data destined to be recorded in the defective sector is actually recorded. More specifically, when a sector designated by the user for recording data is found defective, it is required that the data be recorded in an alternate sector so that the data is in appearance recorded or reproduced at or from the sector designated by the user. This means that a difference may arise between the address of the recording sector designated by the user (i.e. the logical address) and the address of the sector where the data is actually recorded (i.e. the physical address). Under the circumstance, in the hitherto known data recording/reproducing apparatus, correspondence is established between the logical addresses and the physical addresses by resorting to the use of a directory. In the prior art apparatus of this type, it is necessary to update the directory every time the defective sector makes an appearance in the recording mode. Further, retrieval of data can be performed only after the physical address is determined by referring to the directory. Besides, since the directory must be permanently resident in a memory area of the operating system, the capacity required therefor can not be neglected when the number of the sector is large.